This is an open label, non-randomized, multicenter, two-stage, dose escalation Phase I study evaluating single and repeated intratumoral injections of the oncolytic virus, HF10, in patients with refractory head and neck cancer, or solid tumors with cutaneous and/or superficial lesions (e.g., squamous cell carcinoma of the skin, carcinoma of the breast, and malignant melanoma).